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1.
Animals (Basel) ; 10(3)2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-32131471

RESUMO

A better understanding of soil organic carbon (SOC) dynamics is needed when assessing the carbon footprint (CFP) of livestock products and the effectiveness of possible agriculture mitigation strategies. This study aimed (i) to perform a cradle-to-gate CFP of pasture-based beef cattle in a Mediterranean agropastoral system (ii) and to assess the effects on the CFP of alternative tillage, fertilizing, and grazing practices under current (NCC) and future climate change (CC) scenarios. Minimum (Mt) and no-tillage (Nt) practices were compared to current tillage (Ct); a 50% increase (Hf) and decrease (Lf) in fertilization was evaluated against the current (Cf) rate; and rotational grazing (Rg) was evaluated versus the current continuous grazing (Cg) system. The denitrification-decomposition (DNDC) model was run using NCC as well as representative concentration pathways to investigate the effects of farm management practices coupled with future CC scenarios on SOC dynamics, N2O fluxes, and crop yield. Within NCC and CtCf, an emission intensity of 26.9 ± 0.7 kg CO2eq per kg live body weight was estimated. Compared to Ct, the adoption of Mt and Nt reduced the CFP by 20% and 35%, respectively, while NtHf reduced it by 40%. Conservation tillage practices were thus shown to be effective in mitigating greenhouse gas emissions.

2.
J Sci Food Agric ; 98(14): 5518-5524, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29691877

RESUMO

BACKGROUND: Sustainability of food systems is one of the big challenges facing humanity. Local food networks, especially those using organic methods, are proliferating worldwide, and little is known about their carbon footprints. This study aims to assess greenhouse gas (GHG) emissions associated with a local organic beef supply chain using a cradle-to-grave approach. RESULTS: The study determined an overall burden of 24.46 kg CO2  eq. kg-1 of cooked meat. The breeding and fattening phase was the principal source of CO2 in the production chain, accounting for 86% of the total emissions. Enteric methane emission was the greatest source of GHG arising directly from farming activities (47%). The consumption of meat at home was the second high point in GHG production in the chain (9%), with the cooking process being the main source within this stage (72%). Retail and slaughtering activities respectively accounted for 4.1% and 1.1% of GHG emissions for the whole supply chain. CONCLUSION: The identification of the major sources of GHG emissions associated with organic beef produced and consumed in a local food network may stimulate debate on environmental issues among those in the network and direct them toward processes, choices and habits that reduce carbon pollution. © 2018 Society of Chemical Industry.


Assuntos
Dióxido de Carbono/análise , Pegada de Carbono , Carne/análise , Metano/análise , Agricultura Orgânica , Criação de Animais Domésticos , Animais , Dióxido de Carbono/metabolismo , Bovinos/crescimento & desenvolvimento , Bovinos/metabolismo , Culinária , Efeito Estufa
3.
BMC Genomics ; 14: 124, 2013 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-23442185

RESUMO

BACKGROUND: Copy number variations (CNVs) represent a significant source of genomic structural variation. Their length ranges from approximately one hundred to millions of base pair. Genome-wide screenings have clarified that CNVs are a ubiquitous phenomenon affecting essentially the whole genome. Although Bos taurus is one of the most important domestic animal species worldwide and one of the most studied ruminant models for metabolism, reproduction, and disease, relatively few studies have investigated CNVs in cattle and little is known about how CNVs contribute to normal phenotypic variation and to disease susceptibility in this species, compared to humans and other model organisms. RESULTS: Here we characterize and compare CNV profiles in 2654 animals from five dairy and beef Bos taurus breeds, using the Illumina BovineSNP50 genotyping array (54001 SNP probes). In this study we applied the two most commonly used algorithms for CNV discovery (QuantiSNP and PennCNV) and identified 4830 unique candidate CNVs belonging to 326 regions. These regions overlap with 5789 known genes, 76.7% of which are significantly co-localized with segmental duplications (SD). CONCLUSIONS: This large scale screening significantly contributes to the enrichment of the Bos taurus CNV map, demonstrates the ubiquity, great diversity and complexity of this type of genomic variation and sets the basis for testing the influence of CNVs on Bos taurus complex functional and production traits.


Assuntos
Variações do Número de Cópias de DNA , Genoma , Algoritmos , Animais , Bovinos , Hibridização Genômica Comparativa , Biologia Computacional , Genótipo , Polimorfismo de Nucleotídeo Único , Duplicações Segmentares Genômicas , Análise de Sequência de DNA
4.
BMC Proc ; 5 Suppl 4: S20, 2011 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-21645300

RESUMO

BACKGROUND: This preliminary study was aimed at evaluating the association between single nucleotide polymorphisms (SNPs) on Toll like receptor 9 (TLR9) gene and some immunological parameters in a population of Italian Holstein calves. METHODS: The study was carried out in a commercial farm on 68 Holstein calves aging about 6 months. Genomic DNA was extracted from peripheral blood mononuclear cells (PBMC) and genotyped for nine SNPs on TLR9. Immunological parameters considered were the immunoglobulin (Ig) G titers against bovine herpesvirus 1, and the proliferative response of peripheral blood mononuclear cells to mitogens. For the association study, only results relative to the SNP located in the promoter region have been discussed. RESULTS: Among the nine SNPs expected, only eight were detected. Considering the SNP located in the promoter region, all three possible genotypes were observed, and their distribution was as follows: genotype a (n=34), b (n=19), and c (n=8). On the basis of their response to vaccine, calves were categorized as low (L, n=8), medium (M, n=45) and high responders (H, n=8). Although no significant association was found between genotypes and L, M or H categories, the genotype estimated as the less represented within the population (c) had no calves categorized as H, the highest frequency of L (25%), and mean values of IgG lower (P < 0.005) compared to genotype b. Furthermore, IgG titers were positively correlated with responses of PBMC to mitogens. CONCLUSIONS: Genotype c appeared to be "non advantageous" in terms of immune response. It was characterized by the presence of the mutation in homozygosity and, not surprisingly, it was the most rare genotype in the population. Larger studies are necessary in order to confirm these observations.

5.
Cell Stress Chaperones ; 16(4): 441-8, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21274669

RESUMO

Heat shock proteins (Hsp) are known to protect cells from several stressors. Nucleotide changes in the flanking regions [5'- and 3'-untranslated region (UTR)] of Hsp gene might affect inducibility, degree of expression, or stability of Hsp70 mRNA. The present study aimed to investigate the association between inducible Hsp70.1 single nucleotide polymorphisms (SNPs) and heat shock (HS) response of peripheral blood mononuclear cells (PBMC) in dairy cows. Four hundred forty-six Italian Holstein cows were genotyped for four Hsp70.1 SNPs: g895 C/- and g1128 G/T in 5'-UTR, and g2154 G/A and g64 G/T in 3'-UTR. Genetic polymorphisms in 3'-UTR of bovine Hsp70.1 gene resulted monomorphic. Distribution of alleles of the nucleotide sequence polymorphism within the 5'-UTR of the bovine Hsp70.1 gene were 81.2% and 18.8% for C and -, respectively, and 77.8% and 22.2% for G and T, respectively. Among the 446 genotyped animals, a group of cows balanced for days in milk and parity was selected to be representative of the following genotypes: CC (n = 8), C- (n = 7), and -- (n = 7) and GG (n = 8), GT (n = 11), and TT (n = 3) in 5'-UTR. PBMC were isolated from blood samples and heated at 43°C in thermal bath for 1 h and then incubated at 39°C in atmosphere of 5% CO(2) for 1, 2, 4, 8, 16, and 24 h (recovery times). Cell viability was determined by XTT assay. Gene and protein expression of Hsp70.1 was determined by real-time reverse transcription-polymerase chain reaction and by ELISA assay, respectively. For the two SNPs detected, one allele was the most frequent (C, 66.8% and G, 56.8%). Genotypes -- and TG showed higher (P < 0.05) viability compared with CC and GG, respectively. Genotypes C- and TT had intermediate viability. Gene expression of Hsp70.1 showed higher (P < 0.001) levels in -- and TG genotype compared with their counterparts. Genotypes -- and TG showed the higher level of inducible Hsp70.1 protein in respect to C-, TT and CC, GG. In conclusion, exposure to HS differently affected cell viability and gene and protein expression of Hsp70.1 in the selected genotypes. These results indicate that the presence of SNPs (C/- and G/T) in the 5'-UTR region of inducible Hsp70.1 ameliorates HS response and tolerance to heat of bovine PBMC. These mutation sites may be useful as molecular genetic markers to assist selection for heat tolerance.


Assuntos
Proteínas de Choque Térmico HSP70/genética , Resposta ao Choque Térmico/genética , Lactação , Regiões 5' não Traduzidas/genética , Alelos , Animais , Bovinos , Sobrevivência Celular/genética , Sobrevivência Celular/fisiologia , Indústria de Laticínios , Feminino , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/fisiologia , Mutação , Polimorfismo de Nucleotídeo Único/genética
6.
Toxicol In Vitro ; 25(3): 684-91, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21256206

RESUMO

Mycotoxins are secondary metabolites having a high cytotoxic potential. They are produced by molds and released in food and feed. To date, the mechanisms underlying the mycotoxin-induced cytotoxicity have not been fully clarified. The induction of oxidative stress, as a possible mechanism, has been postulated. This in vitro study was focused on the effect of two widely occurring mycotoxins, aflatoxin B(1) (AFB(1)) and fumonisin B(1) (FB(1)), on the oxidative status of bovine peripheral blood mononuclear cells (PBMC) incubated for 2 and 7 days at different levels of AFB(1) (0, 5 and 20 µg/ml) and FB(1) (0, 35 and 70 µg/ml). Reactive oxygen metabolites (ROM), intracellular thiols (SH), malondialdehyde (MDA) and gene expression of cytoplasmic superoxide dismutase (SOD) and glutathione peroxidase (GSHPX-1) were measured on PBMC after incubation. The highest concentration of AFB(1) and all concentrations of FB(1) caused an increase (p<0.05) of intracellular ROM without any time dependent effect. Intracellular SH decreased with 20 µg AFB(1)/ml (p<0.05) and the effect was particularly marked after 7 days of exposure. Intracellular SH were not affected by FB(1) even though a lower (p<0.05) SH level after 2 days exposure than after 7 days was observed. MDA increased (p<0.05) in AFB(1) or FB(1) treated PBMC. The exposure to FB(1) for 7 days increased MDA (p<0.05) only in cells treated with 70 µg/ml. Exposure of PBMC to AFB(1) reduced SOD mRNA while FB(1) decreased both SOD and GSHPX-1 mRNA abundance. These results demonstrate that, even though by different mechanisms, AFB(1) and FB(1) may induce cytotoxicity through an impairment of the oxidative status of PBMC.


Assuntos
Aflatoxina B1/toxicidade , Fumonisinas/toxicidade , Leucócitos Mononucleares/efeitos dos fármacos , Micotoxinas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Animais , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Feminino , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Glutationa/metabolismo , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Leucócitos Mononucleares/metabolismo , Malondialdeído/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Compostos de Sulfidrila/análise , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Glutationa Peroxidase GPX1
7.
Int J Biometeorol ; 55(2): 253-63, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20524014

RESUMO

The study was aimed at describing the temperature humidity index (THI) dynamics over the Mediterranean basin for the period 1951-2007. The THI combines temperature and humidity into a single value, and may help to predict the effects of environmental warmth in farm animals. In particular, on the basis of THI values, numerous studies have been performed to establish thresholds for heat stress in dairy cows. The THI was calculated by using monthly mean values of temperature and humidity obtained from the National Center for Environmental Prediction/National Center for Atmospheric Research reanalysis project. The analysis demonstrated a high degree of heterogeneity of THI patterns over the Mediterranean basin, a strong north-south gradient, and an overall warming during the study period, which was particularly marked during summer seasons. Results indicated that several areas of the basin present summer THI values which were unfavorable to cow welfare and productivity, and that risk of heat stress for cows is generally greater in the countries of the south coast of the basin. Furthermore, THI data from the summer 2003 revealed that severe positive anomalies may impact areas normally characterized by a favorable climate for animal production. In conclusion, THI dynamics should be taken into careful consideration by farmers and policy makers operating in Mediterranean countries when planning investments in the sector of animal production. The investments should at least partially be directed towards implementation of adaptation measures, which may help to alleviate the impact of hot on farm animals welfare, performance and health.


Assuntos
Clima , Interpretação Estatística de Dados , Umidade , Modelos Estatísticos , Temperatura , Tempo (Meteorologia) , Simulação por Computador , Região do Mediterrâneo
8.
Cell Stress Chaperones ; 15(6): 781-90, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20349286

RESUMO

The study was aimed at assessing whether the peri-parturient period is associated with changes of intracellular and plasma inducible heat shock proteins (Hsp) 72 kDa molecular weight in dairy cows, and to establish possible relationships between Hsp72, metabolic, and immunological parameters subjected to changes around calving. The study was carried out on 35 healthy peri-parturient Holstein cows. Three, two, and one week before the expected calving, and 1, 2, 3, 4, and 5 weeks after calving, body conditions score (BCS) was measured and blood samples were collected to separate plasma and peripheral blood mononuclear cells (PBMC). Concentrations of Hsp72 in PBMC and plasma increased sharply after calving. In the post-calving period, BCS and plasma glucose declined, whereas plasma nonesterified fatty acids (NEFA) and tumor necrosis factor-alpha increased. The proliferative responses of PBMC to lipopolysaccharide (LPS) declined progressively after calving. The percentage of PBMC expressing CD14 receptors and Toll-like receptors (TLR)-4 increased and decreased in the early postpartum period, respectively. Correlation analysis revealed significant positive relationships between Hsp72 and NEFA, and between PBMC proliferation in response to LPS and the percentage of PBMC expressing TLR-4. Conversely, significant negative relationships were found between LPS-triggered proliferation of PBMC and both intracellular and plasma Hsp72. Literature data and changes of metabolic and immunological parameters reported herein authorize a few interpretative hypotheses and encourage further studies aimed at assessing possible cause and effect relationships between changes of PBMC and circulating Hsp72, metabolic, and immune parameters in dairy cows.


Assuntos
Bovinos/sangue , Proteínas de Choque Térmico HSP72/metabolismo , Animais , Glicemia/análise , Bovinos/imunologia , Indústria de Laticínios , Ácidos Graxos não Esterificados/sangue , Feminino , Proteínas de Choque Térmico HSP72/sangue , Período Pós-Parto , Receptor 4 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/sangue
9.
Regul Pept ; 160(1-3): 168-74, 2010 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-19963015

RESUMO

Casein phosphopeptides (CPPs) obtained by enzymatic hydrolysis in vitro of caseins, have been shown to enhance calcium solubility and to increase the calcification of embryonic rat bones in their diaphyseal area. Little is known about the direct effects of CPPs on cultured osteoblastic cells. Calcium in the microenvironment surrounding bone cells is not only important for the mineralization of the extracellular matrix, but it is believed to provide preosteblasts with a signal that modulates their proliferation and differentiation. The aim of the present study was to investigate the direct effects of four selected casein phosphopeptides on osteoblastic cell (MC3T3-E1 cells) viability and differentiation. The selected peptides have been obtained by chemical synthesis and differed in the number of phosphorylated sites and in the amino acid spacing out two phosphorylated sites, in order to further characterize the relationship between structure and function. The results obtained in this work demonstrated that CPPs may directly affect osteoblast-like cell growth, calcium uptake and ultimately calcium deposition in the extracellular matrix. The effects exerted by distinct CPPs on osteogenesis in vitro can be either stimulatory or inhibitory. Differential short amino acid sequences in their molecules, like the -SpEE- and the -SpTSpEE-motifs, are likely the molecular determinants for their biological activities on osteoblastic cells. Moreover, two genetic variants of CPPs showing one amino acid change in their sequence may profoundly differ in their biological activities. Finally, our data may also suggest important clues about the role of intrinsic phosphorylated peptides derived from endogenous phosphorylated proteins in bone metabolism, apart from extrinsic CPPs.


Assuntos
Caseínas , Diferenciação Celular/efeitos dos fármacos , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Fosfopeptídeos/farmacologia , Fosfatase Alcalina/metabolismo , Sequência de Aminoácidos , Animais , Cálcio/metabolismo , Comunicação Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ativação Enzimática/efeitos dos fármacos , Camundongos , Dados de Sequência Molecular , Osteoblastos/enzimologia , Fosfopeptídeos/química , Fosfopeptídeos/genética
10.
Res Vet Sci ; 87(3): 396-8, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19482325

RESUMO

This study was performed to ascertain whether a standardized extract from Echinacea angustifolia (Polinacea) affects proliferation and interferon gamma (IFN-gamma) secretion in bovine peripheral blood mononuclear cells (PBMC). PBMC from six Holstein heifers were incubated with 0, 6.3, 20, 60, or 180 microg/ml of the tested compound. Proliferation was stimulated by concanavalin A (ConA) or pokeweed-mitogen (PWM). Secretion of IFN-gamma was stimulated by ConA. All concentrations of Polinacea exerted a mitogenic effect. With respect to control PBMC (0 microg/ml), the lowest and highest increase of proliferation were observed with Polinacea at 6.3 (2-fold increase) or 180 (10-fold increase) microg/ml, respectively. Polinacea at 180 microg/ml reduced ConA-driven proliferation, whereas at 20 and 60 microg/ml improved proliferation of PWM-stimulated PBMC. IFN-gamma secretion was not affected. In conclusion, Polinacea modulates bovine PBMC proliferation, and deserves to be tested in vivo to define conditions that may benefit from its utilization.


Assuntos
Echinacea/química , Interferon gama/metabolismo , Leucócitos Mononucleares/metabolismo , Extratos Vegetais/farmacologia , Animais , Bovinos , Proliferação de Células , Células Cultivadas , Feminino , Mitógenos , Extratos Vegetais/química
11.
J Mol Endocrinol ; 42(2): 139-47, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18996960

RESUMO

Studies have demonstrated that heat shock is associated with alteration in energy metabolism. In this study, we investigated the effect of heat shock on gene expression and secretion of adiponectin and leptin, and gene expression of Hspa2 and Ppargamma in 3T3-L1 adipocytes. Compared with 37 degrees C, adiponectin mRNA was higher at 39 degrees C, and lower at 41 degrees C. Leptin mRNA was higher when adipocytes were exposed to 41 degrees C compared with 37 and 39 degrees C. Secretion of adiponectin increased at 39 degrees C, and when cells were exposed to 41 degrees C it was not detectable. Leptin secretion increased significantly at 41 degrees C, compared with 37 and 39 degrees C. Hspa2 mRNA was increased at 39 degrees C, and the highest level was reached at 41 degrees C. Ppargamma mRNA exhibited a substantial increase in a temperature-dependent manner. The study provides the first evidence of a possible direct effect of heat shock on adiponectin and leptin gene expression and secretion, and demonstrates that the expression of the two adipokines is differentially regulated at the temperatures tested.


Assuntos
Adipócitos/metabolismo , Adiponectina/genética , Resposta ao Choque Térmico , Leptina/genética , Células 3T3-L1 , Adipócitos/citologia , Adiponectina/metabolismo , Animais , Sobrevivência Celular , Regulação da Expressão Gênica , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo , Temperatura Alta , Cinética , Leptina/metabolismo , Camundongos , PPAR gama/genética , PPAR gama/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
12.
Int J Biometeorol ; 50(2): 105-10, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15991017

RESUMO

This study was carried out to ascertain the effects of intense high environmental temperatures (HET) on lymphocyte functions in periparturient dairy cows. The study was undertaken from the beginning of March through the end of July 2003 in a commercial dairy unit located approximately 40 km north of Rome. Thirty-four Holstein cows were utilised in the study. Twenty-two of these cows gave birth in spring (SP cows), from 28 March to 30 April. The remaining 12 cows gave birth in summer (SU cows), between 15 June and 2 July. The two groups of cows were balanced for parity and were fed the same rations. Blood samples were taken 4, 3, 2 and 1 week before calving, and 1, 2 and 4 weeks after calving, in order to evaluate peripheral blood mononuclear cell (PBMC) function in vitro, and to determine plasma cortisol concentrations. After isolation, the PBMC were stimulated with mitogens and their response in terms of DNA synthesis and IgM secretion was measured. During spring, either the day (9-20 h) or the night (21-8 h) temperature humidity index (THI) was below the upper critical THI (72) established for dairy cows. During summer, the mean daily THI values were 79.5+/-2.9 during the day and 70.1+/-4.7 during the night. Furthermore, during summer, three heat waves (a period of at least 3 consecutive days during which there were less than 10 recovery hours) occurred. Recovery hours were intended hours with a THI below 72. The first heat wave lasted 5 days, the second 6 days, and the third 15 days. Compared to the SP cows, over the entire periparturient period the extent of DNA synthesis and IgM secretion levels were lower (P ranging from <0.01 to 0.0001) and higher (P<0.01) respectively, in the SU cows. Before calving, the SU cows also presented higher (P<0.01) concentrations of plasma cortisol compared to the SP cows. This study indicates that the effects of HET on the immune response depend on the specific immune function under consideration, and that neuroendocrinal changes due to HET may play a role in the perturbation of immune functions.


Assuntos
Bovinos/imunologia , Temperatura Alta , Linfócitos/imunologia , Animais , Feminino , Umidade , Hidrocortisona/sangue , Imunoglobulina M/imunologia , Linfócitos/efeitos dos fármacos , Mitógenos/farmacologia , Phytolacca americana
13.
Mamm Genome ; 14(6): 392-5, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12879361

RESUMO

Double muscling is a partially recessive trait present in some beef breeds. It shows a high frequency in some breeds, while in others the frequency is low, and double-muscled individuals are rare. The double muscling is caused by an allelic series of mutations that cause a loss of function of the myostatin gene ( GDF8). We describe here a new mutation in the myostatin gene in Marchigiana breed, a typical beef breed of Central Italy, in which rare double-muscling individuals have been described. A PCR product of the third exon was sequenced in subjects phenotypically showing double muscling, and a G > T transversion was discovered that introduces a premature stop codon. The variant found adds to the large series of mutations present in cattle, and particularly to the only two causative of double muscling in the third exon. A PCR-RFLP test is described for the rapid and effective identification of both heterozygous and homozygous subjects. It was applied to a larger survey carried on the same and also in two other beef breeds, Chianina and Romagnola. Further individuals carrying the new variant were found in Marchigiana, but none in the other breeds. The results may be important for a better comprehension of the role of myostatin in muscular development, for commercial use and for the inference of phylogeny of this gene.


Assuntos
Bovinos/genética , Códon sem Sentido/genética , Doenças Musculares/genética , Doenças Musculares/veterinária , Fator de Crescimento Transformador beta/genética , Animais , Primers do DNA , Itália , Miostatina , Polimorfismo de Fragmento de Restrição , Análise de Sequência de DNA
14.
Am J Vet Res ; 63(7): 958-62, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12118675

RESUMO

OBJECTIVE: To assess effects on functions of peripheral blood mononuclear cells (PBMC) obtained from ewes for each of several fatty acids represented in ovine plasma at concentrations mimicking those of ketotic or healthy ewes. SAMPLE POPULATION: Blood samples obtained from 6 Sardinian ewes. PROCEDURE: The PBMC were cultured in media that contained oleic (OA), palmitic (PA), stearic (SA), linoleic (LA), or palmitoleic (POA) acid at concentrations similar to those of ketotic or healthy ewes. Synthesis of DNA was stimulated by use of concanavalin A or pokeweed mitogen (PWM). Secretion of IgM was stimulated by use of PWM. RESULTS: High concentrations (900, 450, and 225 micromol/L) of OA significantly inhibited DNA synthesis and IgM secretion of PBMC. Conversely, low concentrations (56 or 28 micromol/L) of OA significantly enhanced DNA synthesis of PBMC. High concentrations of PA (600, 300, 150, 75, 375, or 18.7 micromol/L) and SA (300, 150, or 75 micromol/L) significantly inhibited DNA synthesis of PBMC. High concentrations of PA (600, 300, 150, 75, 375, or 18.7 micromol/L) and SA (300, 150, 75, or 38 micromol/L) also significantly inhibited IgM secretion of PBMC. None of the concentrations of LA and POA affected PBMC functions. CONCLUSION AND CLINICAL RELEVANCE: Impaired immunoresponsiveness of ketotic ewes is likely associated with an increase of plasma concentrations of OA, PA, or SA and not with that of LA or POA. At physiologic concentrations, single fatty acids are likely to participate in modulation of immunoresponsiveness by exerting suppressive or stimulatory effects on immune cells.


Assuntos
Ácidos Graxos/sangue , Cetose/veterinária , Leucócitos Mononucleares/metabolismo , Doenças dos Ovinos/sangue , Ovinos/sangue , Animais , Concanavalina A/metabolismo , DNA/biossíntese , Feminino , Imunoglobulina M/biossíntese , Cetose/sangue , Cetose/metabolismo , Mitógenos de Phytolacca americana/metabolismo
15.
Int J Biometeorol ; 46(1): 33-7, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11931096

RESUMO

The study was undertaken during spring and summer months in a territory representative of the Mediterranean climate to assess the effects of season on some immunological parameters of dairy cows. Twenty Holstein cows were used. Eleven of those cows gave birth during spring; the remaining nine cows gave birth in summer. The two groups of cows were homogeneous for parity. Values of air temperatures and relative humidity were recorded both during spring and summer, and were utilized to calculate the temperature humidity index (THI). One week before the expected calving, rectal temperatures and respiratory rates of the cows were recorded (1500 hours), and cell-mediated immunity was assessed by measuring the proliferation of mitogen-stimulated peripheral blood mononuclear cells (PBMC). Within 3 h of calving, one colostrum sample was taken from each cow and analysed to determine content of immunoglobulin (Ig) G1, IgG2, IgM and IgA. At 48 h after birth, passive immunization of the calves was assessed by measuring total serum IgG. During summer, daytime (0900-2000 hours) THI values were above the upper critical value of 72 [75.2, (SD 2.6)] indicating conditions that could represent moderate heat stress. That THI values were able to predict heat stress was confirmed by the values of rectal temperatures and respiratory rates, which were higher (P < 0.05 and P < 0.001 respectively) during summer. Proliferation of PBMC, the colostral concentration of Ig fractions and serum levels of IgG in their respective off-spring did not differ between spring and summer cows. Results indicated that moderate heat stress due to the hot Mediterranean summer does not modify cell-mediated immunity, the protective value of colostrum and passive immunization of the offspring in dairy cows.


Assuntos
Adaptação Fisiológica , Bovinos/imunologia , Transtornos de Estresse por Calor , Imunidade Celular , Imunoglobulinas/análise , Animais , Animais Recém-Nascidos/imunologia , Clima , Colostro/imunologia , Feminino , Umidade , Imunização Passiva , Região do Mediterrâneo , Gravidez , Estações do Ano
16.
Am J Vet Res ; 63(3): 414-8, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11911577

RESUMO

OBJECTIVE: To assess the effects of nonesterified fatty acids (NEFA) and beta-hydroxybutyrate (BHBA) on functions of mononuclear cells obtained from ewes. ANIMALS: 6 Sardinian ewes. PROCEDURE: Mononuclear cells were cultured with concentrations of NEFA (0, 15.6, 31.2, 62.5, 125, 250, 500, 1,000, or 2,000 micromol/L) and BHBA (0, 0.45, 0.9, 1.8, or 3.6 mmol/L). Concentrations of NEFA and BHBA were intended to mimic those of ketotic or healthy ewes, and NEFA and BHBA were tested alone and in combination. Synthesis of DNA was stimulated by use of concanavalin A (Con A) or pokeweed-mitogen (PWM). Secretion of IgM was stimulated by use of PWM. RESULTS: Synthesis of DNA stimulated by Con A and PWM was significantly inhibited by high concentrations of NEFA (> or = 250 micromol/L) or by a combination of high concentrations of NEFA (> or = 250 micromol/L) and all concentrations of BHBA (> or = 0.45 mmol/L). In contrast, DNA synthesis was not inhibited by low concentrations of NEFA (< or = 125 micromol/L) or by a combination of low concentrations of NEFA (< or = 125 micromol/L) and the lowest concentration of BHBA (0.45 mmol/L). Secretion of IgM was significantly inhibited by all concentrations of NEFA and by all combinations of NEFA and BHBA concentrations. When used alone, none of the concentrations of BHBA inhibited DNA synthesis or IgM secretion. CONCLUSIONS AND CLINICAL RELEVANCE: Reduced immunoresponsiveness during ketosis is likely to be associated with an increase in plasma concentration of NEFA and not with an increase in plasma concentration of BH BA.


Assuntos
Ácido 3-Hidroxibutírico/farmacologia , Ácidos Graxos não Esterificados/farmacologia , Leucócitos Mononucleares/efeitos dos fármacos , Ovinos/sangue , Animais , Divisão Celular/efeitos dos fármacos , DNA/biossíntese , DNA/imunologia , DNA/metabolismo , Feminino , Imunoglobulina M/biossíntese , Imunoglobulina M/sangue , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/fisiologia , Ovinos/imunologia
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